Silicon carbide (SiC) is considered as capable of achieving high-temperature performance, high-frequency performance, voltage resistance, and environment resistance each of which could not be achieved by conventional semiconductor materials, such as silicon (Si) and barium arsenide (BaAs), and is therefore expected as a semiconductor material for next-generation power devices and high-frequency devices.
Patent Literature 1 proposes to use a tantalum container having a tantalum carbide layer formed on the surface thereof as a chamber in thermally annealing the surface of a single crystal silicon carbide substrate and in growing a single crystal of silicon carbide on a single crystal silicon carbide substrate. The literature reports that by containing a single crystal silicon carbide substrate in a tantalum container having a tantalum carbide layer on the surface thereof and thermally annealing its surface or growing a silicon carbide single crystal on its surface, a single crystal silicon carbide substrate or a silicon carbide single crystal layer can be formed in which its surface is planarized and has less defects.
Patent Literatures 2 and 3 propose that in allowing carbon to penetrate the surface of tantalum or a tantalum alloy to form tantalum carbide on the surface, Ta2O5 as a naturally oxidized film on the surface is removed by sublimation and carbon is then allowed to penetrate the surface.
However, no specific method for carburizing a tantalum container and a tantalum lid has been discussed in the literatures.